https://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50?tpId=37&&tqId=21233&rp=1&ru=/ta/huawei&qru=/ta/huawei/question-ranking


#include <stdio.h>
#include<string.h>
int main() {
    char arr[500];
    scanf("%s", arr);
    char tmp[128] = { 0 };
    int len = strlen(arr);
    for (int i = 0;i < len;i++)
    {

        if (tmp[arr[i]] == 0)
        {
            tmp[arr[i]] = 1;
        }
    }
    int sum = 0;
    for (int i = 0;i < 128;i++)
    {
        sum += tmp[i];
    }
    printf("%d", sum);


    return 0;
}